EPITHELIAL CARCINOMATA. 



203 



condensation unci conversion into tough, peg-sliaped processes of 

 epitheliumj is in great measure a result of cell-proliferation in 

 the axis of the sprouts themselves. 



§ 168. Passing on to consider the structure of the tumour, 

 (fig. 63a) we see at a glance that it is chiefly made up of the ejji- 

 thelial cylinders already alluded to as '^ peg-shaped protrusions." 

 The average diameter of these cylinders is one-seventh of a line ; 

 their length is usually very considerable, though it is not often 



Fig. ^o. 



Section of an epithelial cylinder under a magnifying power 

 of 500 diameters, a. The cylinder itself, cxliibiting the 

 characteristic stratification of its cells, and tAvo pearly 

 nodules, one of which is older than the other ; h. The 

 stroma ; at c it contains a very large proportion of corpus- 

 cular elements and contributes directly to the additive 

 enlargement of the cylinder. 



that we have an opportunity of seeing the whole of any one- 

 cylinder. They bifurcate, sometimes repeatedly, forming per- 

 fectly dendritic structures. The arrangement of the epithelial 

 cells, as seen in transverse sections, is highly characteristic. At 

 the junction of the epithelium with \\\q connective tissue, at the 

 periphery therefore of the protrusions, a layer of small, roundly- 

 oval elements, often of a brownish tint, is found ; this inter- 

 venes between the connective tissue on the outside^ and the more 



